To me this thread is confusing. So:
First of all you must decide how to partition your drive.
I take it that you only want to install Linux on it? Then what you actually need is just a root partition (mounted at /) and possibly a swap partition.
Note that the root directory (/), which contains everything on the root partition is not the same thing as the /root directory, which is a subdirectory of / and simply the home directory of the root user, a.k.a. the super user or administrator.
An old rule of thumb has for a very long time been that you should create a swap partition that is twice as large as your physical memory. As Old-Polack has pointed out this is still true if you intend to use hibernate on a laptop (or even on a desktop). If you don't and have enough RAM, the size of the swap partition can be radically reduced. If you have more than 4GB of RAM you will only need a swap partition in very rare circumstances; if you have 8GB you probably won't ever need it.
Many users also create a /home partition because by simply not reformatting it they they can retain everything in it if they have to reinstall.
The problem is that by default both your personal settings and your personal data will go into /home/<yourname>. And you might want to keep your data somewhere else. If so you can create a separate data partition, in which case you can let your home partition be overwritten without loosing your photos, text files, music or films.
Some people mount their data partitions on a /Data directory that they create immediately under /. This is not very standards-compliant, so unless you have several users that need access to the directory you should probably create a mountpoint under your home directory.
Traditionally many other directories have been on their own partitions. This is usually not relevant in PCLinuxOS.
But how large should the partitions be? If you have a separate /home partition PCLinuxOS will work well with a root partition of 5GB although 10GB would give you more elbow space. Personally I've managed to fill 30GB, but I love installing and experimenting with all kinds of programs, so I think this should be an upper limit.
If you don't have a separate partition for your data your /home partition can't be too large; if you do have a separate data partition you could just let /home be a subdirectory on a 10GB root partition (/).
For the size of the swap partition, see above.
The actual partitioning can be done in numerous ways. Like many forum members I like to use gparted but diskdrake (which the installation program uses) works quite well.
In your second post you talked about \root and \home, and Old-Polack pointed out that the /root directory isn't usually on its own partition. To that I'd want to add that \ is only used as a symbol for the root directory and as a separator between folders and subfolders in Windows and DOS. In Linux it's just an escape character: it indicates that the following character should be interpreted literally. "\" in Windows is "/" in Linux and other Unix-like systems. (Gates couldn't even get that right.)